Semiconductor device and driving method thereof

ABSTRACT

A semiconductor device having a novel data input and output panel with high definition is provided. A method for driving the semiconductor device having the novel data input and output panel with high definition is provided. The data input and output panel includes, over a substrate, proximity sensors, signal lines electrically connected to the proximity sensors, and pixels electrically connected to the signal lines. The signal lines can supply image signals to the pixels, can supply control signals to the proximity sensors, and can be supplied with sensing signals from the proximity sensors.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an object, a method, or a manufacturingmethod. In addition, the present invention relates to a process, amachine, manufacture, or a composition of matter. In particular, thepresent invention relates to, for example, a semiconductor device, adisplay device, a light-emitting device, a power storage device, adriving method thereof, or a manufacturing method thereof. Specifically,the present invention relates to, for example, a data input and outputpanel and a method for driving the data input and output panel.

2. Description of the Related Art

A CMOS image sensor in which a plurality of imaging elements arearranged in matrix is known.

In addition, an invention having a structure in which transistors whosechannel formation regions are formed using an oxide semiconductor areused as a charge accumulation control transistor and a reset transistoris known. The invention enables a distortion free image to be takenusing the following driving method: after the reset operation of asignal charge accumulation portion is performed in each of imagingelements arranged in matrix, the accumulation operation of charge isperformed by a photodiode in each of imaging elements, and a signal isread from a pixel in each row.

REFERENCE Patent Document

-   [Patent Document 1] Japanese Published Patent Application No.    2011-211699

SUMMARY OF THE INVENTION

In the case where a portable information terminal is used in a user'shand, the hand cannot be freely moved. For this reason, a keyboard,which requires both hands to be used, a mouse, and the like are notsuitable for units for inputting data in a portable information terminalheld by a hand. A unit is desired which allows efficient input of datato a portable information terminal held by a hand even with the use of afinger or the like which cannot be freely moved

In a touch panel, for example, an input unit is integrated into adisplay portion; thus, data visually output on the display portion canbe selected using a finger or the like and input data can be displayedin a region which is pointed out with a finger. Owing to this, anelectronic device including a touch panel allows a user to input andoutput data very intuitively, and as a result, the operationalperformance of the electronic device can be improved.

Further, since a portable information terminal is operated in user'shand, in many cases, the distance between a display portion and user'seyes is short as compared with the cases of a computer, a televisionset, and the like. For this reason, a display portion with pixels whichare so minute that a user cannot recognize the pixels is desired.

To meet those demands, it is necessary to very densely arrange proximitysensors which sense a finger and the like, pixels, a wiring capable ofsupplying signals to the pixels, and the like in a display portion withhigh density.

One embodiment of the present invention is made in view of the foregoingtechnical background. Thus, one object is to provide a semiconductordevice having a novel data input and output panel with high definition.Another object is to provide a method for driving a semiconductor devicehaving a novel data input and output panel with high definition.

Note that the descriptions of these objects do not disturb the existenceof other objects. In one embodiment of the present invention, there isno need to achieve all the objects. Other objects are apparent from andcan be derived from the description of the specification, the drawings,the claims, and the like.

One embodiment of the present invention is a semiconductor device havinga data input and output panel including proximity sensors, signal lineselectrically connected to the proximity sensors, pixels electricallyconnected to the signal lines, and a substrate having an insulatingsurface over which the proximity sensors, the signal lines, and thepixels are provided. The signal lines are configured to supply imagesignals to the pixels and to be supplied with sensing signals from theproximity sensors.

Another embodiment of the present invention is a semiconductor devicehaving a data input and output panel including proximity sensors, signallines electrically connected to the proximity sensors, pixelselectrically connected to the signal lines, and a substrate having aninsulating surface over which the proximity sensors, the signal lines,and the pixels are provided. The signal lines are configured to supplyimage signals to the pixels and to supply control signals to theproximity sensors.

In the data input and output panel of one embodiment of the presentinvention, an electrical connection is made so that one signal line fromwhich an image signal is transferred to pixels can be supplied with asensing signal from a proximity sensor or can supply a control signal tothe proximity sensor. In such a manner, the number of signal lines canbe reduced and as a result, a novel data input and output panel in whichan area occupied by signal lines is reduced without increasing electricresistance of the signal lines can be provided. Alternatively, in such amanner, an extra signal line is unnecessary and as a result, a noveldata input and output panel in which electric resistance of signal linesis reduced without increasing an area occupied by the signal lines canbe provided.

Another embodiment of the present invention is a semiconductor devicehaving a data input and output panel including a first proximity sensor,a second proximity sensor, a signal line electrically connected to thefirst proximity sensor and the second proximity sensor, pixelselectrically connected to the signal line, and a substrate having aninsulating surface over which the first proximity sensor, the secondproximity sensor, the signal line, and the pixels are provided. Thesignal line is configured to supply an image signal to the pixels and tosupply a control signal to the first proximity sensor and the secondproximity sensor.

Another embodiment of the present invention is a semiconductor devicehaving a data input and output panel including a first proximity sensor,a second proximity sensor, a third proximity sensor, a first signal lineelectrically connected to the first proximity sensor, a second signalline electrically connected to the first proximity sensor and the secondproximity sensor, a third signal line electrically connected to thefirst proximity sensor and the third proximity sensor, first pixelselectrically connected to the first signal line, second pixelselectrically connected to the second signal line, third pixelselectrically connected to the third signal line, and a substrate havingan insulating surface over which the first proximity sensor, the secondproximity sensor, the third proximity sensor, the first signal line, thesecond signal line, the third signal line, the first pixels, the secondpixels, and the third pixels are provided. The first signal line isconfigured to supply a first image signal to the first pixels and to besupplied with a sensing signal from the first proximity sensor. Thesecond signal line is configured to supply a second image signal to thesecond pixels and to supply a first control signal to the firstproximity sensor and the second proximity sensor. The third signal lineis configured to supply a third image signal to the third pixels and tosupply a second control signal to the first proximity sensor and thethird proximity sensor.

In the data input and output panel of one embodiment of the presentinvention, an electrical connection is made so that one signal line fromwhich an image signal is transferred to pixels can be supplied with asensing signal from a proximity sensor. In addition, the proximitysensor is supplied with a control signal from the signal line. In such amanner, the number of signal lines can be reduced and as a result, anovel data input and output panel in which an area occupied by signallines is reduced without increasing electric resistance of the signallines can be provided. Alternatively, in such a manner, an extra signalline is unnecessary and as a result, a novel data input and output panelin which electric resistance of signal lines is reduced withoutincreasing an area occupied by the signal lines can be provided.

Another embodiment of the present invention is the above data input andoutput panel in which the proximity sensors are arranged scatteringly ordiscretely in a display portion where the pixels are arranged in matrix.

In the above data input and output panel of one embodiment of thepresent invention, the proximity sensors are arranged scatteringly ordiscretely at predetermined positions in the display portion where thepixels are arranged in matrix. Further, electrical connections are madeso that the signal lines from which image signals are transferred to thepixels can be supplied with sensing signals from the proximity sensors.Accordingly, data can be displayed on the display portion and inaddition, a signal specifying the coordinates in the display portion canbe input. As a result, it is possible to provide a novel data input andoutput panel to which data associated with displayed data can be input.

Another embodiment of the present invention is the above data input andoutput panel further including, over the substrate over which theproximity sensors, the signal lines, and the pixels are provided, aselection circuit for choosing whether to supply image signals orcontrol signals to the signal lines or to be supplied with sensingsignals from the signal lines, a proximity sensor driver circuitelectrically connected to the signal lines, and a pixel driver circuitelectrically connected to the signal lines.

The above data input and output panel of one embodiment of the presentinvention includes, over one substrate, the proximity sensors, thepixels, and the signal lines which can transfer image signals to thepixels and to which sensing signals can be supplied from the proximitysensors. Further, the proximity sensor driver circuit for driving theproximity sensors and the pixel driver circuit are provided over thesame substrate. With such a structure, the proximity sensor drivercircuit and/or the pixel driver circuit can be formed using the sameprocess as the pixel. Accordingly, a novel data input and output panelthat requires a reduced number of manufacturing steps can be provided.

Another embodiment of the present invention is a semiconductor devicehaving a data input and output panel including a proximity sensor, afirst signal line electrically connected to the proximity sensor, asecond signal line electrically connected to the proximity sensor, afirst pixel column electrically connected to the first signal line, asecond pixel column electrically connected to the second signal line, awiring capable of supplying a common potential, and a substrate havingan insulating surface over which the proximity sensor the first signalline, the second signal line, the first pixel column, the second pixelcolumn, and the wiring are provided. The first signal line is configuredto supply an image signal to first pixel column and to be supplied witha sensing signal from the proximity sensor. The second signal line isconfigured to supply an image signal to the second pixel column and tosupply a control signal (e.g., a reset signal) to the proximity sensor.Further, the proximity sensor includes a first transistor, a secondtransistor, and a photoelectric conversion element. A gate and a firstelectrode of the first transistor are electrically connected to thesecond signal line and the wiring capable of supplying the commonpotential, respectively. A gate, a first electrode, and a secondelectrode of the second transistor are electrically connected to asecond electrode of the first transistor, the wiring capable ofsupplying the common potential, and the first signal line, respectively.A first electrode and a second electrode of the photoelectric conversionelement are electrically connected to the wiring capable of supplyingthe common potential and the second electrode of the first transistor,respectively.

Another embodiment of the present invention is a semiconductor devicehaving a data input and output panel including a proximity sensor, afirst signal line electrically connected to the proximity sensor, asecond signal line electrically connected to the proximity sensor, athird signal line electrically connected to the proximity sensor, afirst pixel column electrically connected to the first signal line, asecond pixel column electrically connected to the second signal line, athird pixel column electrically connected to the third signal line, awiring capable of supplying a common potential, and a substrate havingan insulating surface over which the proximity sensor, the first signalline, the second signal line, the third signal line, the first pixelcolumn, the second pixel column, the third pixel column, and the wiringare provided. The first signal line is configured to supply an imagesignal to the first pixel column and to be supplied with a sensingsignal from the proximity sensor. The second signal line is configuredto supply an image signal to the second pixel column and to supply afirst control signal (e.g., a reset signal) to the proximity sensor. Thethird signal line is configured to supply an image signal to the thirdpixel column and to supply a second control signal (e.g., a triggersignal) to the proximity sensor. Further, the proximity sensor includesa first transistor, a second transistor, a third transistor, and aphotoelectric conversion element. A gate and a first electrode of thefirst transistor are electrically connected to the second signal lineand the wiring capable of supplying the common potential, respectively.A gate, a first electrode, and a second electrode of the secondtransistor are electrically connected to a second electrode of the firsttransistor, the wiring capable of supplying the common potential, andthe first signal line, respectively. A gate and a first electrode of thethird transistor are electrically connected to the third signal line andthe second electrode of the first transistor, respectively. A firstelectrode and a second electrode of the photoelectric conversion elementare electrically connected to the wiring capable of supplying the commonpotential and a second electrode of the third transistor, respectively.

The above data input and output panel of one embodiment of the presentinvention includes the pixels, the signal lines, and the proximitysensors each including the photoelectric conversion element. The signallines can supply image signals to the pixels, can supply control signalsto the proximity sensors, and can be supplied with sensing signals fromthe proximity sensors. In such a manner, the number of signal lines canbe reduced and as a result, a novel data input and output panel in whichan area occupied by signal lines is reduced without increasing electricresistance of the signal lines can be provided. Alternatively, in such amanner, an extra signal line is unnecessary and as a result, a noveldata input and output panel in which electric resistance of signal linesis reduced without increasing an area occupied by the signal lines canbe provided.

Another embodiment of the present invention is a method for driving theabove data input and output panel including the steps of: supplyingimage signals to pixels electrically connected to the first signal line,the second signal line, and the third signal line; supplying the firstcontrol signal (e.g., a reset signal) to the proximity sensor; supplyingthe second control signal (e.g., a trigger signal) to the proximitysensor; and acquiring the sensing signal supplied from the proximitysensor.

In the above method for driving the data input and output panel of oneembodiment of the present invention, after supply of one frame imagesignal from one signal line to the pixels in the display portion, areset signal is supplied to the proximity sensor, a trigger signal issupplied to the proximity sensor, and a sensing signal is acquired fromthe proximity sensor. In this manner, data can be displayed on thedisplay portion. Further, data can be input using a sensing signalacquired from the proximity sensor. Accordingly, a method for driving asemiconductor device having a novel data input and output panel withhigh definition display and high input resolution can be provided.

In this specification, one of a first electrode and a second electrodeof a transistor refers to a source electrode and the other refers to adrain electrode.

One embodiment of the present invention can provide a semiconductordevice having a novel data input and output panel with high definition.Another embodiment of the present invention can provide a method fordriving a semiconductor device having a novel data input and outputpanel with high definition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are block diagrams each illustrating a configuration of adata input and output panel of an embodiment.

FIGS. 2A and 2B are block diagrams each illustrating a configuration ofa data input and output panel of an embodiment.

FIGS. 3A, 3B1, 3B2, and 3C are block diagrams each illustrating aconfiguration of a data input and output panel of an embodiment.

FIG. 4 is a block diagram illustrating a configuration of a data inputand output panel of an embodiment.

FIGS. 5A and 5B are block diagrams illustrating a configuration of adata input and output panel of an embodiment.

FIGS. 6A to 6C are block diagrams and a circuit diagram illustrating aconfiguration of a proximity sensor that can be used in a data input andoutput panel of an embodiment.

FIGS. 7A to 7C are block diagrams and a circuit diagram illustrating aconfiguration of a proximity sensor that can be used in a data input andoutput panel of an embodiment.

FIGS. 8A and 8B are a block diagram and a circuit diagram forillustrating a selection circuit that can be used in a data input andoutput panel of an embodiment.

FIG. 9 is a timing chart illustrating operation of a data input andoutput panel of an embodiment.

FIGS. 10A and 10B are circuit diagrams each illustrating a configurationof a proximity sensor that can be used in a data input and output panelof an embodiment.

FIGS. 11A to 11E are diagrams each illustrating an electronic device ofan embodiment.

DETAILED DESCRIPTION OF THE INVENTION

To achieve the above objects, one embodiment of the present invention ismade with a focus on a proximity sensor, a signal line, a pixel, andelectrical connections thereof. This leads to a semiconductor devicethat can be used for a data input and output panel having a structureexemplified in this specification.

A data input and output panel of one embodiment of the present inventionincludes, over a substrate, proximity sensors, signal lines electricallyconnected to the proximity sensors, and pixels electrically connected tothe signal lines. The signal lines can supply image signals to thepixels, can supply control signals to the proximity sensors, and can besupplied with sensing signals from the proximity sensors. In such amanner, the number of signal lines can be reduced and as a result, anovel data input and output panel in which an area occupied by signallines is reduced without increasing electric resistance of the signallines can be provided. Alternatively, in such a manner, an extra signalline is unnecessary and as a result, a novel data input and output panelin which electric resistance of signal lines is reduced withoutincreasing an area occupied by the signal lines can be provided.

Embodiments will be described in detail with reference to drawings. Notethat the present invention is not limited to the following description,and it will be easily understood by those skilled in the art thatvarious changes and modifications can be made without departing from thespirit and scope of the present invention. Accordingly, the presentinvention should not be interpreted as being limited to the content ofthe embodiments below. In the structures of the invention to bedescribed below, the same portions or portions having similar functionsare denoted by the same reference numerals in different drawings, andexplanation thereof will not be repeated.

Embodiment 1

In this embodiment, configurations of a data input and output panel ofone embodiment of the present invention will be described with referenceto FIGS. 1A to 1C and FIGS. 2A and 2B.

FIG. 1A is a top view of the data input and output panel of oneembodiment of the present invention. FIGS. 1B and 1C are block diagramseach illustrating a configuration of a display portion in which a signalline, a pixel, and a proximity sensor are provided.

A data input and output panel 100 includes a substrate 101 having aninsulating surface and a display portion 106. The display portion 106includes a plurality of pixel columns 105 each of which has pixelsconnected to one signal line (see FIG. 1A). Note that one of theplurality of pixel columns 105 is referred to as a pixel column 105(x),a pixel column 105(x+1), or the like.

The data input and output panel of one embodiment of the presentinvention includes the pixel column 105(x) (see FIG. 1B). The pixelcolumn 105(x) includes a proximity sensor 104(x), a signal line 102(x)electrically connected to the proximity sensor 104(x), and a pixel103(x) electrically connected to the signal line 102(x).

Note that the signal line 102(x) can supply an image signal 91 v(x) tothe pixel 103(x) and can be supplied with a sensing signal 92 i from theproximity sensor 104(x).

Alternatively, the data input and output panel of one embodiment of thepresent invention includes a pixel column 105(x−1) (see FIG. 1C). Thepixel column 105(x−1) includes a proximity sensor 104(x), a signal line102(x−1) electrically connected to the proximity sensor 104(x), and apixel 103(x−1) electrically connected to the signal line 102(x−1).

Note that the signal line 102(x−1) can supply an image signal 91 v(x−1)to the pixel 103(x−1) and can supply a control signal 92 c to theproximity sensor 104(x).

In the data input and output panel of one embodiment of the presentinvention, an electrical connection is made so that one signal line fromwhich an image signal is transferred to the pixel can be supplied with asensing signal from the proximity sensor. In such a manner, the numberof signal lines can be reduced and as a result, a novel data input andoutput panel in which an area occupied by signal lines is reducedwithout increasing electric resistance of the signal lines can beprovided. Alternatively, in such a manner, an extra signal line isunnecessary and as a result, a novel data input and output panel inwhich electric resistance of signal lines is reduced without increasingan area occupied by the signal lines can be provided. Note that in somecases, other effects or objects are achieved by the data input andoutput panel of one embodiment of the present invention.

A data input and output panel of another embodiment of the presentinvention includes a first proximity sensor 104(x), a second proximitysensor 104(x−1), a signal line 102(x−1) electrically connected to thefirst proximity sensor 104(x) and the second proximity sensor 104(x−1),and a pixel 103(x−1) electrically connected to the signal line 102(x−1)(see FIG. 2A).

Note that the signal line 102(x−1) can supply an image signal 91 v(x−1)to the pixel 103(x−1) and can supply a control signal 92 c (e.g., areset signal) to the first proximity sensor 104(x) and the secondproximity sensor 104(x−1).

A data input and output panel of another embodiment of the presentinvention includes, over a substrate having an insulating surface, afirst proximity sensor 104(x), a second proximity sensor 104(x−1), athird proximity sensor 104(x+1), a first signal line 102(x), a secondsignal line 102(x−1), and a third signal line 102(x+1) (see FIG. 2B).

The first signal line 102(x) is electrically connected to the firstproximity sensor 104(x) and a plurality of pixels. Further, the firstsignal line 102(x) can supply an image signal 91 v(x) to the pixels andcan be supplied with a sensing signal 92 i from the first proximitysensor 104(x).

The second signal line 102(x−1) is electrically connected to the firstproximity sensor 104(x), the second proximity sensor 104(x−1), and aplurality of pixels. The second signal line 102(x−1) can supply an imagesignal to the pixels and can supply a first control signal (e.g., areset signal) to the first proximity sensor 104(x) and the secondproximity sensor 104(x−1).

The third signal line 102(x+1) is electrically connected to the firstproximity sensor 104(x), the third proximity sensor 104(x+1), and aplurality of pixels. The third signal line 102(x+1) can supply an imagesignal to the pixels and can supply a second control signal (e.g., atrigger signal) to the first proximity sensor 104(x) and the thirdproximity sensor 104(x+1).

In the data input and output panel of one embodiment of the presentinvention, an electrical connection is made so that one signal line fromwhich an image signal is transferred to the pixel can be supplied with asensing signal from the proximity sensor. In such a manner, the numberof signal lines can be reduced and as a result, a novel data input andoutput panel in which an area occupied by signal lines is reducedwithout increasing electric resistance of the signal lines can beprovided. Alternatively, in such a manner, an extra signal line isunnecessary and as a result, a novel data input and output panel inwhich electric resistance of signal lines is reduced without increasingan area occupied by the signal lines can be provided. Note that in somecases, other effects or objects are achieved by the data input andoutput panel of one embodiment of the present invention.

Elements included in the data input and output panel of one embodimentof the present invention will be described below.

<<Substrate Having Insulating Surface>>

The substrate 101 has an insulating surface. The substrate 101 may be aconductive substrate, or a substrate having semiconductorcharacteristics on which an insulating film is stacked.

Note that the substrate 101 has heat resistance high enough to withstandthe manufacturing process and are not particularly limited in thicknessand size as long as they can be applied to a manufacturing apparatus. Inaddition, the substrate 101 may have a single-layer structure or alayered structure including two or more layers.

Examples of a material that can be used for the substrate 101 includeglass, ceramics, a metal, an inorganic material, and a resin in aplate-like shape or a film-like shape, and a stack including some ofthese materials.

<<Proximity Sensor>>

The proximity sensor 104(x) has a function of sensing the proximity of afinger or the like. As the proximity sensor, a capacitive proximitysensor, an electromagnetic inductive proximity sensor, a photo-detectiontype proximity sensor, or the like can be used, for example.

A capacitive proximity sensor includes an electrode forming an electricfield and operates using a phenomenon in which the capacitance of theelectrode is changed by an object approaching a region where an electricfield is formed. Such a sensor can sense the proximity of a fingertip,for example.

An electromagnetic inductive proximity sensor includes an oscillationcircuit forming a magnetic field and operates using a phenomenon inwhich the circuit constant of the oscillation circuit is changed bycurrent flowing in an object approaching a region where a magnetic fieldis formed. Such a sensor can sense the proximity of a stylus including apiece of metal or a coil, for example.

A photo-detection type proximity sensor includes a photoelectricconversion element for sensing brightness and operates with the strengthof light blocked by, reflected by, or emitted from an object approachinga region where light can be sensed.

Note that a specific example of a photo-detection type proximity sensorwill be described in detail in Embodiment 4.

<<Signal Line>>

The first signal line 102(x), the second signal line 102(x−1), the thirdsignal line 102(x+1), and the like have conductivities and are formedover the insulating surface of the substrate 101. In the case where acircuit is formed over the insulating surface of the substrate 101, awiring of the circuit can be formed using the same conductive film asthe signal line.

For example, the first signal line 102(x) can supply an image signal tothe pixels and can be supplied with a sensing signal from the firstproximity sensor 104(x).

The second signal line 102(x−1) can supply an image signal to the pixelsand can supply a first control signal (e.g., a reset signal) to thefirst proximity sensor 104(x) and the second proximity sensor 104(x−1).

The third signal line 102(x+1) can supply an image signal to the pixelsand can supply a second control signal (e.g., a trigger signal) to thefirst proximity sensor 104(x) and the third proximity sensor 104(x+1).

Note that a specific example of a configuration in which a pixel and aphoto-detection type proximity sensor are connected by a wiring will bedescribed in detail in Embodiment 4.

<<Pixel>>

Image signal are supplied to the pixel 103(x−1), the pixel 103(x), andthe like and as a result, an image is displayed. Each of the pixelsincludes a display element and a pixel circuit for driving the displayelement.

As the display element, any of a variety of display elements, such as anelectro-optic element, a light-emitting element, and electronic ink, canbe used.

Examples of an electro-optic element include a liquid crystal elementand a display element including an optical interference element or ashutter controlled by micro electro mechanical systems (MEMS).

As the light-emitting element, an electroluminescent element or an LEDcan be used, for example.

Further, a circuit which is suitable for driving the display elementused is selected as the pixel circuit.

This embodiment can be combined with any of the other embodiments inthis specification as appropriate.

Embodiment 2

In this embodiment, arrangements of proximity sensors included in a datainput and output panel of one embodiment of the present invention willbe described with reference to FIGS. 3A, 3B1, 3B2, and 3C and FIG. 4.

The data input and output panel of one embodiment of the presentinvention includes sub-pixels arranged in matrix over an insulatingsurface and proximity sensors arranged instead of some of thesub-pixels.

FIG. 3A is a top view illustrating a structure of the data input andoutput panel of one embodiment of the present invention. FIGS. 3B1, 3B2,and 3C are schematic diagrams each illustrating an arrangement ofproximity sensors in a display portion 106 illustrated in FIG. 3A. Notethat pixels are not illustrated in the drawings for simplicity.

FIG. 4 is a schematic top view of the data input and output panel of oneembodiment of the present invention.

In a data input and output panel 100 described as an example in thisembodiment, proximity sensors 104 are arranged scatteringly ordiscretely in the display portion 106 where the pixels are arranged inmatrix.

The proximity sensors 104 are connected to signal lines but are notelectrically connected to scan lines connected to the pixels. As aresult, the proximity sensors 104 can be freely arranged in the displayportion 106 without consideration of an arrangement of the scan lines.

For example, the proximity sensors 104 can be arranged in matrix equallyin the display portion 106. Specifically, the proximity sensors 104 maybe arranged at intersections of a square lattice (solid lines in FIG. 3B1). Alternatively, the proximity sensors 104 may be arranged atintersections of a rhombic lattice (solid lines in FIG. 3B2). When theproximity sensors 104 are arranged almost equally in the display portion106, distributions of the number of pixels per proximity sensors 104 inthe display portion 106 can be substantially the same. Such a structureis preferable because an image with less unevenness and the like can bedisplayed.

Alternatively, the proximity sensors 104 can be arranged unequally inthe display portion 106 (see FIG. 3C). For example, the proximitysensors 104 are arranged with high density in a region whose coordinatesneed to be input exactly and with low density in a region whosecoordinates are roughly input or not input. In such a case, timerequired for acquiring data from a region to which data is input lessfrequently can be allotted to a region to which data is input morefrequently in the input and output panel.

In the above data input and output panel of one embodiment of thepresent invention, the proximity sensors are arranged scatteringly ordiscretely at predetermined positions in the display portion where thepixels are arranged in matrix. Further, electrical connections are madeso that the signal lines from which image signals are transferred to thepixels can be supplied with sensing signals from the proximity sensors.Accordingly, data can be displayed on the display portion and inaddition, a signal specifying the coordinates in the display portion canbe input through the proximity sensors. As a result, it is possible toprovide a novel data input and output panel to which data associatedwith displayed data can be input.

<<Arrangement Example of Proximity Sensors and Sub-Pixels>>

The case where proximity sensors driven with four signal lines areprovided in a display portion will be described as an example withreference to FIG. 4.

A data input and output panel 100B includes a display portion. Thedisplay portion includes two stages 106 a and 106 b and pixels in amatrix of 1136 rows and 640 columns.

The stage 106 a and the stage 106 b each include 363520 (=568 rows×640columns) pixels in matrix at a resolution of 326 ppi.

One pixel is composed of three sub-pixels and one sub-pixel is providedat an intersection of one scan line and one signal line. One sub-pixelis driven using signals supplied from one scan line and one signal line.This means that 568 scan lines and 1920 (=640×3) signal lines areprovided in one stage.

In the case of using the proximity sensors driven with four signallines, 480 (=1920÷4) proximity sensors can be arranged in one stage,which indicates that one in every about 757 (363520÷480) pixels can bereplaced with one proximity sensor. For example, one proximity sensorcan be provided in a region where sub-pixels are arranged in a matrix of27 rows×27 columns, that is, in a region where pixels are arranged in amatrix of 27 rows×9 columns (in approximately 0.083 inches×0.028inches).

Note that an area occupied by one proximity sensor is preferably smallerthan or equal to that of one pixel. Further, the resolution of the pixelin the display portion is preferably 300 ppi or more and furtherpreferably 326 ppi or more. In that case, a proximity sensor providedinstead of a pixel can be hardly distinguished with naked eyes and areduction in the quality of a displayed image can be suppressed.

According to the above estimation, in the data input and output panel100B, one in every about 757 pixels is replaced with one proximitysensor 104. Although the amount of light emitted from the pixels isreduced when a pixel is replaced with a proximity sensor, the reductionis only approximately 0.13%. This indicates that the data input andoutput panel 100B is more favorable than a structure in which severalpercent of light emitted from a display portion is blocked by acapacitive touch sensor overlapping with the display portion.

This embodiment can be combined with any of the other embodiments inthis specification as appropriate.

Embodiment 3

In this embodiment, a configuration of a data input and output panel ofone embodiment of the present invention will be described with referenceto FIGS. 5A and 5B.

FIG. 5A is a block diagram illustrating a structure of the data inputand output panel of one embodiment of the present invention. FIG. 5B isa schematic top view of the data input and output panel for illustratingan arrangement of circuits.

The data input and output panel described as an example in thisembodiment includes, over a substrate over which a proximity sensor104(x), signal lines 102, and pixels (e.g., a pixel 103(x)) areprovided, a selection circuit 109 for choosing whether to supply imagesignals or control signals to the signal lines 102 or to be suppliedwith sensing signals from the signal lines 102, a proximity sensordriver circuit 108 electrically connected to the signal lines 102, and apixel driver circuit 107 s electrically connected to the signal lines102 (see FIG. 5A).

The above data input and output panel of one embodiment of the presentinvention includes, over one substrate, the proximity sensor, thepixels, and the signal lines which can transfer image signals to thepixels and to which sensing signals can be supplied from the proximitysensor. Further, the proximity sensor driver circuit 108 for driving theproximity sensor and the pixel driver circuit 107 s are provided overthe same substrate (see FIG. 5B). With such a structure, the proximitysensor driver circuit 108 and/or the pixel driver circuit 107 s can beformed using the same process as the pixel. Accordingly, the novel datainput and output panel 100C that requires a reduced number ofmanufacturing steps can be provided.

Note that a scanning line driver circuit 107 g may be provided over thesubstrate 101. The selection circuit 109, the proximity sensor drivercircuit 108, the pixel driver circuit 107 s, and the scanning linedriver circuit 107 g can be formed over the same substrate in the samestep.

Individual components included in a data input and output panel 100C ofone embodiment of the present invention will be described below. Notethat the components are not necessarily provided individually and onecomponent may be integrated with another component.

<<Scanning Line Driver Circuit>>

The scanning line driver circuit 107 g is electrically connected to aplurality of scan lines 112. The scan lines 112 extend to the displayportion 106 and a plurality of pixels are electrically connected to onescan line.

Further, the scanning line driver circuit 107 g can supply a signal forselecting one scan line. Accordingly, pixels electrically connected tothe selected scan line can be selected.

<<Pixel Driver Circuit>>

The pixel driver circuit 107 s is electrically connected to theselection circuit 109.

Further, the pixel driver circuit 107 s can supply an image signal. Notethat the pixel driver circuit 107 s is supplied with an image signalVIDEO.

The scanning line driver circuit 107 g and the pixel driver circuit 107s can be each configured with a logic circuit (e.g., a shift register)including a combination circuit.

Further, the scanning line driver circuit 107 g and the pixel drivercircuit 107 s are supplied with a power supply potential and a controlsignal (e.g., a start pulse or a clock signal).

<<Proximity Sensor Driver Circuit>>

The proximity sensor driver circuit 108 is electrically connected to theselection circuit 109.

The proximity sensor driver circuit 108 can be supplied with a sensingsignal and can supply a sensing signal SENS.

The proximity sensor driver circuit 108 can be, for example, aparallel-serial conversion circuit including a combination circuit.

<<Selection Circuit>>

The selection circuit 109 is electrically connected to the pixel drivercircuit 107 s, the proximity sensor driver circuit 108, and the signallines 102.

The selection circuit 109 is preferably provided between the pixeldriver circuit 107 s and the display portion 106. Further, the selectioncircuit 109 is preferably provided between the proximity sensor drivercircuit 108 and the display portion 106.

When the selection circuit 109 is provided closer to the display portion106, wirings can be prevented from intersecting and an increase inparasitic capacitance or wiring resistance can be prevented orsuppressed, for example.

Note that the selection circuit 109 can be incorporated in anothercircuit.

The selection circuit 109 is supplied with power supply potentials PWRand control signals CTL (e.g., a start pulse and a clock signal).

The selection circuit 109 can choose whether to supply an image signalor a control signal to the signal line 102 or to be supplied with asensing signal from the signal line 102.

Further, the selection circuit 109 has two modes.

In a first mode, a supplied image signal is supplied to the signal line102.

Note that one signal line is electrically connected to a plurality ofpixels (or a pixel column). Accordingly, an image signal can be suppliedto pixels (e.g., the pixel 103(x)) electrically connected to a scan lineselected by the scanning line driver circuit 107 g.

This means that the data input and output panel operates as an activematrix display panel in a period during which the selection circuit 109is in the first mode.

In a second mode, a control signal is supplied to one signal line and asensing signal is supplied from a different signal line. Note that thetwo signal lines are electrically connected to one proximity sensor(e.g., the proximity sensor 104(x)). Accordingly, the proximity sensorcan be supplied with a control signal and can supply a sensing signal.

A specific configuration example of the selection circuit 109 will bedescribed in Embodiment 5 with reference to FIGS. 8A and 8B.

This embodiment can be combined with any of the other embodiments inthis specification as appropriate.

Embodiment 4

In this embodiment, data input and output panels of one embodiment ofthe present invention will be described with reference to FIGS. 6A to 6Cand FIGS. 7A to 7C.

FIG. 6A is a top view of the data input and output panel of oneembodiment of the present invention. FIG. 6B is a block diagramillustrating a configuration of a display portion in which a signalline, a pixel, and a proximity sensor are provided. FIG. 6C is a circuitdiagram illustrating a proximity sensor that can be used in the datainput and output panel.

A data input and output panel 100D described as an example in thisembodiment includes a substrate 101 having an insulating surface andover the insulating surface, a proximity sensor 104(x), a first signalline 102(x) electrically connected to the proximity sensor 104(x), asecond signal line 102(x−1) electrically connected to the proximitysensor 104(x), a first pixel column 105(x) electrically connected to thefirst signal line 102(x), a second pixel column 105(x−1) electricallyconnected to the second signal line 102(x−1), and a wiring capable ofsupplying a common potential Vcom are provided (see FIGS. 6A and 6B).Note that a scanning line driver circuit is electrically connected to aplurality of scan lines 112. The scan lines 112 extend to a displayportion 106 and a plurality of pixels are electrically connected to onescan line.

The first signal line 102(x) can supply an image signal to the firstpixel column 105(x) and can be supplied with a sensing signal from theproximity sensor 104(x).

The second signal line 102(x−1) can supply an image signal 91 v(x−1) tothe second pixel column 105(x−1) and can supply a control signal 92 c(e.g., a reset signal) to the proximity sensor 104(x).

The proximity sensor 104(x) includes a first transistor 121(1), a secondtransistor 121(2), and a photoelectric conversion element 122. A gateand a first electrode of the first transistor 121(1) are electricallyconnected to the second signal line 102(x−1) and the wiring capable ofsupplying the common potential Vcom, respectively. A gate, a firstelectrode, and a second electrode of the second transistor 121(2) areelectrically connected to a second electrode of the first transistor121(1), the wiring capable of supplying the common potential Vcom, andthe first signal line 102(x), respectively. A first electrode and asecond electrode of the photoelectric conversion element areelectrically connected to the wiring capable of supplying the commonpotential Vcom and the second electrode of the first transistor 121(1),respectively (see FIG. 6C).

Modification Example

A modification example of a data input and output panel of oneembodiment of the present invention will be described with reference toFIGS. 7A to 7C.

FIG. 7A is a top view of the data input and output panel of oneembodiment of the present invention. FIG. 7B is a block diagramillustrating a configuration of a display portion in which a signalline, a pixel, and a proximity sensor are provided. FIG. 7C is a circuitdiagram illustrating a proximity sensor that can be used in the datainput and output panel.

Note that a data input and output panel 100E illustrated in FIGS. 7A to7C is the same as the data input and output panel illustrated in FIGS.6A to 6C except that a proximity sensor which is driven by beingsupplied with two kinds of control signals are used and the connectionsof signal lines are different.

The data input and output panel described as an example in thisembodiment includes a substrate 101 having an insulating surface andover the insulating surface, a proximity sensor 104(x), a first signalline 102(x) electrically connected to the proximity sensor 104(x), asecond signal line 102(x−1) electrically connected to the proximitysensor 104(x), a third signal line 102(x+1) electrically connected tothe proximity sensor 104(x), a first pixel column 105(x) electricallyconnected to the first signal line 102(x), a second pixel column105(x−1) electrically connected to the second signal line 102(x−1), athird pixel column 105(x+1) electrically connected to the third signalline 102(x+1), and a wiring capable of supplying a common potential Vcomare provided.

The first signal line 102(x) can supply an image signal to the firstpixel column 105(x) and can be supplied with a sensing signal from theproximity sensor 104(x).

The second signal line 102(x−1) can supply an image signal to the secondpixel column 105(x−1) and can supply a first control signal (e.g., areset signal) to the proximity sensor 104(x).

The third signal line 102(x+1) can supply an image signal to the thirdpixel column 105(x+1) and can supply a second control signal (e.g., atrigger signal) to the proximity sensor 104(x).

The proximity sensor 104(x) includes a first transistor 121(1), a secondtransistor 121(2), a third transistor 121(3), and a photoelectricconversion element 122. A gate and a first electrode of the firsttransistor 121(1) are electrically connected to the second signal line102(x−1) and the wiring capable of supplying the common potential Vcom,respectively. A gate, a first electrode, and a second electrode of thesecond transistor 121(2) are electrically connected to a secondelectrode of the first transistor 121(1), the wiring capable ofsupplying the common potential Vcom, and the first signal line 102(x),respectively. A gate and a first electrode of the third transistor121(3) are electrically connected to the third signal line 102(x+1) andthe second electrode of the first transistor 121(1), respectively. Afirst electrode and a second electrode of the photoelectric conversionelement are electrically connected to the wiring capable of supplyingthe common potential Vcom and a second electrode of the third transistor121(3), respectively.

The above data input and output panel of one embodiment of the presentinvention includes the pixels, the signal lines, and the proximitysensors each including the photoelectric conversion element. The signallines can supply image signals to the pixels, can supply control signalsto the proximity sensors, and can be supplied with sensing signals fromthe proximity sensors. In such a manner, the number of signal lines canbe reduced and as a result, a novel data input and output panel in whichan area occupied by signal lines is reduced without increasing electricresistance of the signal lines can be provided. Alternatively, in such amanner, an extra signal line is unnecessary and as a result, a noveldata input and output panel in which electric resistance of signal linesis reduced without increasing an area occupied by the signal lines canbe provided.

Modification Example

Modification examples of a proximity sensor that can be used in the datainput and output panel of one embodiment of the present invention aredescribed with reference to FIGS. 10A and 10B. FIGS. 10A and 10B arecircuit diagrams each illustrating a proximity sensor that can be usedin the data input and output panel of one embodiment of the presentinvention.

Proximity sensors each driven with four signal lines are illustrated inFIGS. 10A and 10B. Specifically, a proximity sensor 120A and a proximitysensor 120B are each electrically connected to a first signal line SL1,a second signal line SL2, a third signal line SL3, and a fourth signalline SL4.

The first signal line SL1 can supply a signal (sensing signal) generatedwhen the proximity sensor senses the proximity of an object. The secondsignal line SL2 can supply a signal (reset signal) for making theproximity sensor to be in an initial state. The third signal line SL3can supply a signal (trigger signal) for determining a period duringwhich the proximity sensor senses the proximity of an object.

The proximity sensor 120A illustrated as an example in FIG. 10A isconnected to the fourth signal line SL4 capable of supplying a commonpotential Vcom. The proximity sensor 120A includes a first transistor121 a(1), a second transistor 121 a(2), and a third transistor 121 a(3).A gate and a first electrode of the first transistor 121 a(1) areelectrically connected to the second signal line SL2 and the fourthsignal line SL4, respectively. A gate, a first electrode, and a secondelectrode of the second transistor 121 a(2) are electrically connectedto a second electrode of the first transistor 121 a(1), the fourthsignal line SL4, and the first signal line SL1, respectively. A gate anda first electrode of the third transistor 121 a(3) are electricallyconnected to the third signal line SL3 and the second electrode of thefirst transistor 121 a(1), respectively. In addition, a photoelectricconversion element 122 a whose first electrode and second electrode areelectrically connected to the fourth signal line SL4 and the secondelectrode of the third transistor 121 a(3), respectively, is included.

The proximity sensor 120B illustrated as an example in FIG. 10B isconnected to the fourth signal line SL4 capable of supplying a highpower supply potential VDD and a wiring capable of supplying a commonpotential Vcom. The proximity sensor 120B includes a first transistor121 b(1), a second transistor 121 b(2), and a third transistor 121 b(3).A gate and a first electrode of the first transistor 121 b(1) areelectrically connected to the second signal line SL2 and the wiringcapable of supplying the common potential Vcom, respectively. A gate, afirst electrode, and a second electrode of the second transistor 121b(2) are electrically connected to a second electrode of the firsttransistor 121 b(1), the wiring capable of supplying the commonpotential Vcom, and the first signal line SL1, respectively. A gate anda first electrode of the third transistor 121 b(3) are electricallyconnected to the third signal line SL3 and the second electrode of thefirst transistor 121 b(1), respectively. In addition, a light dependentresistor 122 b (also referred to as a photoresistor) whose firstelectrode and second electrode are electrically connected to the fourthsignal line SL4 and the second electrode of the third transistor 121b(3), respectively, is included.

This embodiment can be combined with any of the other embodiments inthis specification as appropriate.

Embodiment 5

In this embodiment, a selection circuit that can be used in a data inputand output panel of one embodiment of the present invention will bedescribed with reference to FIGS. 5A and 5B and FIGS. 8A and 8B.

FIG. 5A is a block diagram illustrating a structure of the data inputand output panel of one embodiment of the present invention. FIG. 5B isa schematic top view for illustrating an arrangement of circuitsincluded in the data input and output panel.

FIG. 8A is a block diagram illustrating a configuration of the selectioncircuit 109 that can be used in the data input and output panel of oneembodiment of the present invention. FIG. 8B is a circuit diagramillustrating a proximity sensor that can be used in the data input andoutput panel of one embodiment of the present invention.

The selection circuit 109 illustrated in FIG. 8A can be used in the datainput and output panel 100E described in Embodiment 4 with reference toFIGS. 7A to 7C.

<Data Input and Output Panel>

In this embodiment, the selection circuit 109 that can be used in thedata input and output panel 100C described in Embodiment 3 will bedescribed as an example of a selection circuit (see FIGS. 5A and 5B).

The data input and output panel 100C that can include the selectioncircuit 109 described as an example in this embodiment includes thesubstrate 101 having an insulating surface and the proximity sensor104(x) over the substrate 101 (see FIGS. 5A and 5B). The data input andoutput panel 100C further includes a first signal line 102(x), a secondsignal line 102(x−1), and a third signal line 102(x+1) which areelectrically connected to the proximity sensor 104(x) (see FIGS. 5A and5B and FIGS. 8A and 8B).

Further, the data input and output panel 100C also includes a firstpixel column 105(x) electrically connected to the first signal line102(x), a second pixel column 105(x−1) electrically connected to thesecond signal line 102(x−1), and a third pixel column 105(x+1)electrically connected to the third signal line 102(x+1).

In addition, the data input and output panel 100C includes a wiring 83capable of supplying a high power supply potential VDD, a wiring 84capable of supplying a low power supply potential VSS, which is lowerthan the high power supply potential VDD, and a wiring capable ofsupplying a common potential Vcom (see FIGS. 8A and 8B).

The data input and output panel 100C further includes a control signalline 85 a, a control signal line 85 b, and a control signal line 85 cwhich can supply signals CTL for controlling operation of the selectioncircuit 109. Note that the control signal line 85 a, the control signalline 85 b, and the control signal line 85 c can supply a control signalFR, a control signal RE, and a control signal EX, respectively.

<Selection Circuit>

The selection circuit 109 is electrically connected to the pixel drivercircuit 107 s, the proximity sensor driver circuit 108, and the signallines 102.

The selection circuit 109 selects and supplies a power supply potentialor a control signal for driving the proximity sensor 104(x) connected tothe three signal lines, and is supplied with a sensing signal from theproximity sensor 104(x).

Note that FIG. 8A illustrates only components electrically connected tothree signal lines which are necessary to drive the proximity sensor104(x) among the signal lines 102, and the other signal lines are notillustrated for simplicity and clarity of the configuration of theselection circuit 109. Further, FIG. 8B illustrates only the proximitysensor 104(x) and the other proximity sensors are not illustrated.

Specifically, the case where the proximity sensor 104(x) having the sameconfiguration as the modification example described in Embodiment 4 withreference to FIG. 7C is driven with the first signal line 102(x), thesecond signal line 102(x−1), and the third signal line 102(x+1) isdescribed.

The selection circuit 109 includes a plurality of switches. Theselection circuit 109 described as an example includes three switcheselectrically connected to the three signal lines. A transistor is usedas a switch in this embodiment; however, one embodiment of the presentinvention is not limited thereto.

The selection circuit 109 includes a switch 51 a and a switch 51 b. Oneterminal of the switch 51 a and one terminal of the switch 51 b areelectrically connected to the first signal line 102(x). The selectioncircuit 109 also includes a switch 51 c whose one terminal iselectrically connected to an output terminal of an inverter circuit 55.Note that an input terminal of the inverter circuit 55 is electricallyconnected to the first signal line 102(x).

The other terminal of the switch 51 a, the other terminal of the switch51 b, and the other terminal of the switch 51 c are electricallyconnected to a signal line 107 SL(x) that can supply an image signal,the wiring 83 capable of supplying the high power supply potential VDD,and a wiring capable of supplying a sensing signal, respectively.

The selection circuit 109 further includes a switch 52 a, a switch 52 b,and a switch 52 c. One terminal of the switch 52 a, one terminal of theswitch 52 b, and one terminal of the switch 52 c are electricallyconnected to the second signal line 102(x−1).

Note that the other terminal of the switch 52 a, the other terminal ofthe switch 52 b, and the other terminal of the switch 52 c areelectrically connected to a signal line 107 SL(x−1) that can supply animage signal, the wiring 83 capable of supplying the high power supplypotential VDD, and the wiring 84 capable of supplying the low powersupply potential VSS, respectively.

The selection circuit 109 also includes a switch 53 a, a switch 53 b,and a switch 53 c. One terminal of the switch 53 a, one terminal of theswitch 53 b, and one terminal of the switch 53 c are electricallyconnected to the third signal line 102(x+1). Note that the otherterminal of the switch 53 a, the other terminal of the switch 53 b, andthe other terminal of the switch 53 c are electrically connected to asignal line 107 SL(x+1) that can supply an image signal, the wiring 84capable of supplying the low power supply potential VSS, and the wiringcapable of supplying the high power supply potential VDD, respectively.

The switch 51 a, the switch 52 a, and the switch 53 a turn on or off inaccordance with the control signal FR supplied from the control signalline 85 a. The switch 51 b, the switch 52 b, and the switch 53 b turn onor off in accordance with the control signal RE supplied from thecontrol signal line 85 b. The switch 51 c, the switch 52 c, and theswitch 53 c turn on or off in accordance with the control signal EXsupplied from the control signal line 85 c.

<Driving Method>

A method for driving the data input and output panel of one embodimentof the present invention will be described with reference to FIGS. 8Aand 8B and FIG. 9.

Note that the proximity sensor 104(x) illustrated in FIG. 8B has thesame configuration as the proximity sensor 104(x) described inEmbodiment 4 with reference to FIG. 7C; thus, the descriptions inEmbodiment 4 are referred to here. Note that a node where the secondelectrode of the first transistor 121(1) and the gate of the secondtransistor 121(2) are connected to each other is a node m.

<<First Step>>

In a first step, an image signal is supplied to pixels electricallyconnected to the first signal line 102(x), the second signal line102(x−1), or the third signal line 102(x+1) (see FIG. 8A and a period T1in FIG. 9). This period is also referred to as a frame period.

Specifically, the control signal line 85 a supplies the control signalFR so that the switch 51 a, the switch 52 a, and the switch 53 a areturned on.

The control signal line 85 b supplies the control signal RE so that theswitch 51 b, the switch 52 b, and the switch 53 b are turned off. Thecontrol signal line 85 c supplies the control signal EX so that theswitch 51 c, the switch 52 c, and the switch 53 c are turned off.

<<Second Step>>

In a second step, a first control signal (also referred to as a resetsignal) is supplied to the proximity sensor 104(x) (see FIGS. 8A and 8Band a period T2 in FIG. 9).

Specifically, the control signal line 85 b supplies the control signalRE so that the switch 51 b, the switch 52 b, and the switch 53 b areturned on. Thus, the high power supply potential VDD is supplied to thefirst signal line 102(x) and the second signal line 102(x−1) and the lowpower supply potential VSS is supplied to the third signal line102(x+1).

The control signal line 85 a supplies the control signal FR so that theswitch 51 a, the switch 52 a, and the switch 53 a are turned off. Thecontrol signal line 85 c supplies the control signal EX so that theswitch 51 c, the switch 52 c, and the switch 53 c are turned off.

As a result, the second signal line 102(x−1) supplies the high powersupply potential VDD to the gate of the first transistor 121(1) to turnon the first transistor 121(1); accordingly, the potential of the node mbecomes the common potential Vcom. Note that when the potential of thenode m becomes the common potential Vcom, the proximity sensor 104(x) isinitialized.

<<Third Step>>

In a third step, a second control signal (also referred to as a triggersignal) is supplied to the proximity sensor 104(x) (see FIGS. 8A and 8Band a period T3 in FIG. 9).

Specifically, the control signal line 85 c supplies the control signalEX so that the switch 51 c, the switch 52 c, and the switch 53 c areturned on. Thus, a sensing signal is supplied from the proximity sensor104(x) to the first signal line 102(x). Further, the low power supplypotential VSS is supplied to the second signal line 102(x−1) and thehigh power supply potential VDD is supplied to the third signal line102(x+1).

The control signal line 85 a supplies the control signal FR so that theswitch 51 a, the switch 52 a, and the switch 53 a are turned off. Thecontrol signal line 85 b supplies the control signal RE so that theswitch 51 b, the switch 52 b, and the switch 53 b are turned off.

As a result, the second signal line 102(x−1) supplies the low powersupply potential VSS to the gate of the first transistor 121(1) to turnoff the first transistor 121(1). Further, the third signal line 102(x+1)supplies the high power supply potential VDD to the gate of the thirdtransistor 121(3) to turn on the third transistor 121(3). Accordingly,the potential of the node m becomes higher than the common potentialVcom by a voltage generated by the electromotive force of thephotoelectric conversion element 122.

The potential of the node m is supplied to the gate of the secondtransistor 121(2). The common potential Vcom is supplied to the firstelectrode of the second transistor 121(2). The voltage generated by theelectromotive force of the photoelectric conversion element 122 isapplied between the first electrode and the gate of the secondtransistor 121(2).

In the case where the voltage generated by the electromotive force ofthe photoelectric conversion element 122 exceeds the threshold value ofthe second transistor 121(2), the potential of the first signal line102(x) to which the high power supply potential VDD is supplied in thesecond step is reduced to the common potential Vcom; thus, a sensingsignal is supplied from the proximity sensor 104(x).

In the driving method of one embodiment of the present invention, atrigger signal can be input to a plurality of proximity sensors providedin an input and output panel at almost the same time. As a result, anumber of proximity sensors can be driven in a short period of time(e.g., in a blanking period). This means that the input and output panelcan be driven by a global shifter system.

In the input and output panel including a number of proximity sensors,when the proximity sensors receive proximity data by a global shiftersystem and supply sensing signals, and the sensing signals are acquiredin succession, there is a time lapse after acquisition of a signal by aproximity sensor and before acquisition of a signal by another proximitysensor. When the potential of the node m changes because of this timelapse, a signal cannot be acquired accurately. Thus, a transistor whosefirst electrode or second electrode is connected to the node mpreferably has a small off-leakage current.

Specifically, a transistor whose a channel formation region is formedusing an oxide semiconductor and whose off-leakage current is extremelysmall is preferably used as the first transistor 121(1). In particular,a transistor formed using an oxide semiconductor containing indium ispreferable.

Note that in this embodiment, the proximity sensor 104(x) supplies asensing signal to the inverter circuit 55 through the first signal line102(x) and supplies a signal with inverted polarity to the proximitysensor driver circuit 108 through the switch 51 c.

Note that the potential of the node m is changed by the electromotiveforce of the photoelectric conversion element 122.

The proximity sensor 104(x) senses an object approaching the proximitysensor 104(x) by detecting a change in the amount of light incident onthe proximity sensor 104(x).

In the case where a finger or the like approaches the proximity sensorso as to block light, for example, the electromotive force of thephotoelectric conversion element 122 is small. Thus, a change in thepotential of the node m which has become the common potential Vcom inthe second step is smaller than that in the case where no objectapproaches to block light.

In the case where a finger or the like does not approaches the proximitysensor and light enters without being blocked, the electromotive forceof the photoelectric conversion element 122 is large. Thus, a change inthe potential of the node m which has become the common potential Vcomin the second step is larger than that in the case where an objectapproaches to block light.

<<Fourth Step>>

In a fourth step, the sensing signal supplied from the proximity sensor104(x) is acquired (see FIGS. 8A and 8B and a period T4 in FIG. 9).

Specifically, the control signal line 85 a supplies the control signalFR so that the switch 51 a, the switch 52 a, and the switch 53 a areturned off. The control signal line 85 b supplies the control signal REso that the switch 51 b, the switch 52 b, and the switch 53 b are turnedoff. The control signal line 85 c supplies the control signal EX so thatthe switch 51 c, the switch 52 c, and the switch 53 c are turned off.

In this embodiment, the proximity sensor 104(x) supplies the sensingsignal to the proximity sensor driver circuit 108 in the third step.

The proximity sensor driver circuit 108 may invert the supplied sensingsignal into a serial signal and output the serial signal in the fourthstep.

<<Repeating the Steps>>

After that, the first to fourth steps are repeated. Specifically, in aperiod T5, in a manner similar to that in the period T1, an image signalis supplied to the pixels electrically connected to the first signalline 102(x), the second signal line 102(x−1), or the third signal line102(x+1).

The periods T1 and T5 in FIG. 9 can be referred to as frame periodsduring which image data is written to the data input and output panel.Further, a period between the period T1 and the period T5 can be calleda blanking period. Thus, one embodiment of the present invention can bereferred to as a method for driving a data input and output panelincluding the step of supplying a reset signal and a trigger signal to aproximity sensor in a blanking period to acquire a sensing signal fromthe proximity sensor.

In the above method for driving the data input and output panel of oneembodiment of the present invention, one frame image signal is suppliedto the pixels in the display portion, a reset signal is supplied to theproximity sensor, a trigger signal is supplied to the proximity sensor,and a sensing signal is acquired from the proximity sensor. In thismanner, data can be displayed on the display portion. Further, data canbe input using a sensing signal acquired from a proximity sensor whichis provided at known coordinates. Accordingly, a method for driving asemiconductor device having a novel data input and output panel withhigh definition display can be provided.

This embodiment can be combined with any of the other embodiments inthis specification as appropriate.

Embodiment 6

In this embodiment, electronic devices of one embodiment of the presentinvention will be described with reference to FIGS. 11A to 11E.

An electronic device of one embodiment of the present invention includesany of the semiconductor devices each having a data input and outputpanel of one embodiment of the present invention and can display imagedata. For example, video data broadcasted or distributed or video datastored in a data storage medium can be displayed. Further, dataprocessed by a data processing device can be displayed. Furthermore, animage used for operation of a control panel or the like can bedisplayed.

Examples of an electronic device displaying video data include atelevision device and a digital photo frame.

Examples of the data processing device include a computer, a digitalcamera, a digital video camera, and a portable information terminal.

Examples of an electronic device including a control panel include amobile phone, a portable game machine, a large-scale game machine (e.g.,a pachinko machine), and an audio reproducing device.

<Television Device>

A television device 7100 includes a display portion 7103 incorporated ina housing 7101 supported by a stand 7105 (see FIG. 11A).

An image displayed on the display portion 7103 of the television device7100, a channel, volume, or the like is controlled using a separateremote controller 7110.

The remote controller 7110 includes a data input and output panel 7107,an operation key 7109, and the like.

An image displayed on the display portion 7103 is supplied from areceiver or a modem for receiving data broadcasted or distributed.

The television device 7100 may be connected to Internet to performtwo-way (e.g., between a sender and a receiver or between receivers)communication of data.

<Data Processing Device>

FIG. 11B illustrates a computer as an example of the data processingdevice. The computer includes a main body 7201, a housing 7202, a datainput and output panel 7203, a keyboard 7204, an external connectionport 7205, a pointing device 7206, and the like.

<Game Machine>

FIG. 11C illustrates an example of a portable game machine. A portablegame machine illustrated as an example includes two housings, a housing7301 and a housing 7302, which are jointed with a joint portion 7303 sothat the portable game machine can be opened or folded. A data input andoutput panel 7304 is incorporated in the housing 7301 and a data inputand output panel 7305 is incorporated in the housing 7302.

In addition, the portable game machine includes a speaker portion 7306,a recording medium insertion portion 7307, an LED lamp 7308, an inputmeans (an operation key 7309, a connection terminal 7310, a sensor 7311(a sensor having a function of measuring force, displacement, position,speed, acceleration, angular velocity, rotational frequency, distance,light, liquid, magnetism, temperature, chemical substance, sound, time,hardness, electric field, current, voltage, electric power, radiation,flow rate, humidity, gradient, oscillation, odor, or infrared rays), ora microphone 7312), and the like.

The portable game machine has a function of reading a program or datastored in a recording medium to display it on the data input and outputpanel, and a function of sharing information with another portable gamemachine by wireless communication.

<Mobile Phone>

FIG. 11D illustrates an example of a mobile phone. A cellular phone 7400is provided with a data input and output panel 7402 incorporated in ahousing 7401, an operation button 7403, an external connection port7404, a speaker 7405, a microphone 7406, and the like.

The data input and output panel 7402 includes a proximity sensor; thus,data can be input when a finger or the like touches or approaches thedata input and output panel 7402.

When a sensing device including a sensor such as a gyroscope or anacceleration sensor for detecting inclination is provided, display onthe screen of the data input and output panel 7402 can be automaticallychanged in direction by determining the orientation of the cellularphone 7400 (whether the cellular phone 7400 is placed horizontally orvertically for a landscape mode or a portrait mode).

The data input and output panel 7402 can function as a two-dimensionalimage sensor. In that case, images of a palm print and a fingerprint ofa hand which touches the data input and output panel 7402, images of apalm vein and a finger vein which can be taken using a backlight or asensing light source emitting near-infrared light, and the like can beused for personal authentication, for example.

<Portable Information Terminal>

FIG. 11E illustrates an example of a foldable portable informationterminal. A portable information terminal 7450 includes a housing 7451Land a housing 7451R connected by hinges 7454. The portable informationterminal 7450 further includes an operation button 7453, a left speaker7455L, and a right speaker 7455R. In addition, a side surface of theportable information terminal 7450 is provided with an externalconnection port 7456, which is not illustrated. Note that when theportable information terminal 7450 is folded on the hinges 7454 so thata data input and output panel 7452L provided in the housing 7451L and adata input and output panel 7452R provided in the housing 7451R can faceeach other, the data input and output panels can be protected by thehousings.

Further, the portable information terminal 7450 can also include agyroscope, an acceleration sensor, a global positioning system (GPS)receiver, or a video camera. For example, when a detection deviceincluding a sensor for detecting inclination, such as a gyroscope or anacceleration sensor, is provided, the orientation of the display screencan be automatically changed by determining the orientation of theportable information terminal 7450 (whether the portable informationterminal 7450 is placed horizontally or vertically).

Furthermore, the portable information terminal 7450 can be connected toa network. The portable information terminal 7450 not only can displaydata on the Internet but also can be used as a terminal which controlsanother electronic device connected to the network from a distant place.

This embodiment can be combined with any of the other embodiments inthis specification as appropriate.

This application is based on Japanese Patent Application serial no.2013-040649 filed with Japan Patent Office on Mar. 1, 2013, the entirecontents of which are hereby incorporated by reference.

What is claimed is:
 1. A semiconductor device comprising: a displayportion having a pixel over a substrate; a proximity sensor in thedisplay portion; and a signal line electrically connected to theproximity sensor and the pixel, wherein the signal line is configured tosupply an image signal to the pixel and to be supplied with a sensingsignal from the proximity sensor.
 2. The semiconductor device accordingto claim 1, wherein the signal line is configured to supply a controlsignal to the proximity sensor.
 3. The semiconductor device according toclaim 1, further comprising: a circuit configured to supply the imagesignal to the signal line and to be supplied with the sensing signalfrom the signal line; a proximity sensor driver circuit electricallyconnected to the circuit; and a pixel driver circuit electricallyconnected to the proximity sensor driver circuit.
 4. The semiconductordevice according to claim 3, wherein the circuit is configured to supplya control signal to the signal line.
 5. A semiconductor devicecomprising: a display portion having first and second pixels over asubstrate; a first proximity sensor in the display portion; a firstsignal line electrically connected to the first proximity sensor and thefirst pixel; and a second signal line electrically connected to thefirst proximity sensor and the second pixel, wherein the first signalline is configured to supply a first image signal to the first pixel andto be supplied with a sensing signal from the first proximity sensor,and wherein the second signal line is configured to supply a secondimage signal to the second pixel and to supply a control signal to thefirst proximity sensor.
 6. The semiconductor device according to claim5, wherein the first proximity sensor comprises: a first transistorhaving: a gate electrode electrically connected to the second signalline; and a first electrode electrically connected to a wiringconfigured to supply a common potential to the first proximity sensor; asecond transistor having: a gate electrode electrically connected to asecond electrode of the first transistor; a first electrode electricallyconnected to the wiring; and a second electrode electrically connectedto the first signal line; and a photoelectric conversion element having:a first electrode electrically connected to the wiring; and a secondelectrode electrically connected to the second electrode of the firsttransistor.
 7. The semiconductor device according to claim 5, furthercomprising: a circuit configured to supply the first and second imagesignals to the first and second signal lines, respectively, to supplythe control signal to the second signal line, and to be supplied withthe sensing signal from the first signal line; a proximity sensor drivercircuit electrically connected to the circuit; and a pixel drivercircuit electrically connected to the proximity sensor driver circuit.8. The semiconductor device according to claim 5, further comprising asecond proximity sensor electrically connected to the second signalline.
 9. A semiconductor device comprising: a display portion havingfirst, second, and third pixels over a substrate; a first proximitysensor in the display portion; a first signal line electricallyconnected to the first proximity sensor and the first pixel; a secondsignal line electrically connected to the first proximity sensor and thesecond pixel; and a third signal line electrically connected to thefirst proximity sensor and the third pixel, wherein the first signalline is configured to supply a first image signal to the first pixel andto be supplied with a sensing signal from the first proximity sensor,wherein the second signal line is configured to supply a second imagesignal to the second pixel and to supply a first control signal to thefirst proximity sensor, and wherein the third signal line is configuredto supply a third image signal to the third pixel and to supply a secondcontrol signal to the first proximity sensor.
 10. The semiconductordevice according to claim 9, wherein the first proximity sensorcomprises: a first transistor having: a gate electrode electricallyconnected to the second signal line; and a first electrode electricallyconnected to a wiring configured to supply a common potential to thefirst proximity sensor; a second transistor having: a gate electrodeelectrically connected to a second electrode of the first transistor; afirst electrode electrically connected to the wiring; and a secondelectrode electrically connected to the first signal line; a thirdtransistor having: a gate electrode electrically connected to the thirdsignal line; and a first electrode electrically connected to the secondelectrode of the first transistor; and a photoelectric conversionelement having: a first electrode electrically connected to the wiring;and a second electrode electrically connected to a second electrode ofthe third transistor.
 11. The semiconductor device according to claim 9,further comprising: a circuit configured to supply the first, second,and third image signals to the first, second, and third signal lines,respectively, to supply the first and second control signals to thesecond and third signal lines, respectively, and to be supplied with thesensing signal from the first signal line; a proximity sensor drivercircuit electrically connected to the circuit; and a pixel drivercircuit electrically connected to the proximity sensor driver circuit.12. The semiconductor device according to claim 9, further comprising: asecond proximity sensor electrically connected to the second signalline; and a third proximity sensor electrically connected to the thirdsignal line.
 13. A method for driving a semiconductor device comprisinga display portion having first and second pixels and a proximity sensor,the method comprising the steps of: supplying a first image signal tothe first pixel via a first signal line; supplying a second image signalto the second pixel via a second signal line; supplying a control signalto the proximity sensor via the second signal line; and acquiring asensing signal supplied from the proximity sensor via the first signalline.